Switch for lathes



May 26, 19421- H. D. MARTIN y 2,284,464

- d swITcH FomLATHE Filed May 27, 1940 ATTORNEYS Patented May 26, 1942UNITED i fsi" SWITCH Foa LATnEs Harry D. Martin, Albion, N. Y. iApplication May 27, 1940, serial No. 337,524 1 claim. (c1. 20o-4i) Thepresent invention relates to automatic lathes and more particularlyvto anovel switch for automatically stopping thelathe. y

The primary object of the invention resides in the provision of a motorout out switch that is adapted to'be clamped to the bed of a latheforstopping said lathe upon the cutting tool reaching a predeterminedposition thereby prec-luding the possibility of injury to the tool.

A further object of theinvention is to provide a switch that may beattached at any position along the bed of the lathe and which will serveas an automatic power cut oi for the motor after the movable cuttingtool has completed its travel along the work thereby eliminatingconstant attention of the operator of the lathe.

A still further object of the invention resides in the provision of anautomatic cut out switch having the above characteristics that willsubstantially eliminate the possibility of ruined stock due tocarelessness of the operator.

The invention will be fully and comprehensively understood from aconsideration of the following detailed description when read inconnection with the accompanying drawing which forms a part of theapplication.

In the drawing:

Figure 1 is a transverse sectional view through the bed of an automaticlathe and illustrating the present invention applied thereto.

Figure 2 is a top plan view of the device.

Figure 3 is a vertical sectional View taken substantially on line 3-3 ofFigure 1.

Referring to the drawing for a more detailed description thereof, thebed of a lathe is generally designated by the reference numeral 5, andas is customary, said bed comprises spaced rails 6 and l, respectively,which guide the travel of the automatic cutting tool and compound rest,not shown. In accordance with the present invention the motor cut outswitch generally designated by the reference numeral 8 is adapted to beattached at any position along the lathe bed so as to be contacted bythe compound rest for stopping the lathe motor when the cutting tool hasreached the end of the work.

The switch 8 comprises a substantially squareshaped metal case 9, saidcase having a cover Il! removably attached thereto by screws or otherfastening means I I. A push rod I2 is mounted in the cover IUsubstantially centrally thereof,

said push rod extending within the case as shown v in Figure 3 and alsoprojecting exteriorly of the case, the projecting end having attachedthereto a bumper I3. A spring Ill is carried on the rod "f I2, the samebeing held between the bumper I3 and cover Il for returning said pushrod to nor.- mal position upon the release of pressure on the bumperI3.l I

A pair ofA switch arms I5 and I6, respectively,

' are mounted within the casing 8, the same being supported by means ofthe pair of screws I1. It will be noted that the screws I1 are disposedwithin insulating sleeves I8 and that insulating washers I9 are providedfor maintaining the switch arms I5 and I6 in spaced relation. The switcharms are slidably disposed over the insulating sleeves I8 and the entireassembly is united by means of the washers 30. The lower end of the armsI5 and IB are connected as indicated at 20 in circuit with the motor 2lof the lathe. Switch points 22 and 23 are mounted on the arms I5 and I6,respectively, and when in contact the circuit to the motor is complete.A bumper washer 24, formed of fiber or the like, is carried by the upperend of the switch arm I6 and is adapted to be contacted by the inner endof the push rod l2 for separatingV the contacts 22 and 23. v

The switch casing 8 is adjustably mounted on the lathe bed 5through themedium of a bar 25 secured as indicated at 26 to the cover of rthecasing, said bar being disposed above the bed and being held thereto bymeans of the clamps 2'! and bolts 28.

In use, the switch casing will be adjustably mounted on the lathe bed soas to b'e contacted by the compound rest as soon as the tool hascompleted its travel over the work. The compound rest will contact thebumper I3 of the push rod I2 urging said push'rod inwardly into contactwith the washer 24 effecting disengagement of the switch contacts 22 and23 breaking the circuit to the lathe motor 2l.

As the rest is moved away from the bumper, the spring VIll will returnthe push rod to normal position thereby bringing the contacts 22 and 23together permitting further operation of the moto-r 2|,

A manually operable switch 3l is provided which, of course, is normallyclosed for operating the lathe motor. The switch arms I5 and I6 operateto stop the motor while theswitch is in closed position. I

It will be readily understood that the switch can be positioned on thelathe bed so as to function without the attention of the operator tostop the lathe as soon as the tool has completed its travel of the workthereby precluding the possibility of injury to the tool, Work or otherparts of the lathe.

Also it will be understood, -of course, by those skilled in the art thatvariations in th'e hereinabove described device involving thesubstitution of substantial equivalents for the devices describedareintended to be comprehended within the spirit of the present inventionand that the invention is capable of extended application vand is notconi-ined to the exactshowing of the drawing norv to thepreciseconstruction described and, therefore, such changes and modications maybe made therein as do not affect the spirit of the invention nor exceedthe scope thereo as expressed in therappendedrclaim.

What is claimedris: Y In automatically operable switch mechanism forlathes, a rectangular shaped casing, a barof the rod,V a bumper elementfastened on the outer end of the rod, a spring sleeved about the Vouterportion of therrod between the casing and Y complementary arm softhat afree end portion thereof` projects'vertically beyond the free` end oftheother arm, the saidY extended end portion r. of the resilient armbeing in horizontal alignment secured to the casing and projectinglaterally j' thereof, a pair of clampsrcarriedby the said bar forremovably `connecting the bar to a lathe,

the said casing havingY a bore through one end thereof, a horizontallydisposed-push rod slidably extended through the said bore, thesaid rodhaving an enlarged portion at its inner end form-- ing a shoulder forlimiting theoutward movement with the push rod and normally separatedtherefrom, and a pair of contact elements secured to the respective armsand'disposed to assume contacting circuit closing positions when theresil.

ient arm is released 'and to assume separated cir-4 cuitopeningpositionwhen the uresilient arm is swung laterally byy retractionof the `push rod by a Amovable portion of the lathe.

' HARRY D. MARTIN.

